Didn't the T-Rex give us any lessons? Once thought to be primarily a hunter, it is now considered mostly a scavenger. Now comes a new analysis of the Sabre-Tooth Tiger suggesting the primary use of beefy forelimbs developed to assist in restraining struggling prey.
It strikes me that it would be much more likely for the saber-tooth to use it's powerful forelegs and fangs for, respectively and primarily, fighting and threat displays isn't it?
After investing all those calories in growing gigantic teeth, why spend even more hauling big forelimbs at high acceleration in hunting chases when scaring off smaller predators who actually conducted the kill would be so much more efficient? The primary source of calories for similar big cats in Africa today is via this method after smaller cats like hyenas "bring home the bacon".
If truly effective for hunting, large teeth such as those of the sabre-tooth and powerful forelimbs would seem best suited only for quick ambushes or very short chases, and sexual differentiation in "upper" body structure could be an important clue in unraveling their competitive advantage which, like the fangs, would seem on first glance more of more evolutionary value in real or symbolic threats against competing males for mating rights and displays for females.